Electrical system and device therefor



April 13, 1937. D. s. KENNEDY 2,076,849

ELECTRICAL SYSTEM AND DEVICE THEREFOR Filed Nov. 26, 1954 2 Sheets-Sheet l 5k 23 INVENTOR.

1 l BY $4. 74 -h ATTORNEYS.

April 13, 1937- n D. s. KENNEDY 2,076,849

ELECTRICAL SYSTEM AND DEVICE THEREFOR Filed NOV. 26, 1954 2 Sheets-Sheet 2 lll/4 '111. VII 'lll 'IIIA71Aflllllllllllllllftlllj INVENTOR. l

: ATTORNEYS.

Patented Apr. 13, 1937 2,07?,849 ELECTRICAL SYSTEFIVAND DEVICE THERE- Donald S. Kennedy, New York, N. Y. Application November 26, 1934, Serial No. 754,918

11 claims. (ci. 1v1-'97) f UNITED STATES PATENT OFFICE This invention relates to electrical systems and switches therefor and more particularly to switches capable of furnishing either or both continuous and intermittent electrical energy to signal lamps, either function being performed independent of, or simultaneously with, the other. It has special application for lighting lcircuits used in advertising and display devices, electrical signs and signalling circuits etc., and it may be advantageously employed as a substitute for the con- .ventional automobile stop light switch.

.u An object of the invention is to provide an 'electrical switch for operating an alarm signal either audible or visible in. an enhancedly attention compelling manner.

Another object of the invention is to present an electrical switch capable of producing a ramiiled electrical current by which a plurality of signals may be operated each in a unique manner.

Another object of the invention is to produce an economically constructed electrical switch, wherein the switch contacts together with a circuit breaking element, control the current to one or more electric lamps; whereby the closing of the switch contacts will cause any or all of the lamps to immediately light, either uninterruptedly, or intermittently,

' Another object of the invention is to produce a novel advertising means for the automobile trade whose operation will cause the` signal lights to function so differently from all others, that cars thus equipped will be continuously identifiable upon the highways both day and night by the 'action of the signal lamps.

With the above and other objects in view one embodiment of the invention may be illustrated .by substituting this device in lieu of the customary stop light switches commonly found connected in the lighting circuit of an automobile. My switch receives the normally unvarying current from the car storage battery, or other source of electrical energy, and is capable of continuing or discontinuing the current drawn therefrom at will and can transmit the same either unaltered or can convert the normally unvarying current into a modified current e. g. into pulsating direct current, interrupted direct current, interrupted alternating current, or alternating current having` a regularly irregular cyclic alternation of low frequency. etc. Thus this unaltered or the modiiied current is fed by the switch to one or more auxiliary signal lamps usually located on the rear of a motor driven vehicle, and in the event that said vehicle is equipped with two or more signal lamps unaltered and modified current may be simultaneously conducted to said signal lamps. This current is fed at the will of the operator either by manually operating the switch, or the switch itself can be connected with the braking mechanism of the automobile so that its operation 'may become automatic upon the application of the brakes. The signal lamps will then glow either steadily or in a modified fashion, e. g. will pulsate rhythmically or blink on and off, or a combination of both continuous lighting and blinking simultaneously.

Other objects and features of the invention will appear from the following detailed description of one embodiment thereof taken in connection with the accompanying drawings in which identical reference numerals are applied to identical parts in the several iigures and in which Fig. 1 is a longitudinal section through an automobile stop light switch embodying my invention, taken on line I I of Fig. 2;

Fig. 2 is a view, taken on line 2-2 of Figures -1 and 3;

circuit for an automobile; andv Fig. 7 is a similar representation of a modified form thereof.

Referring at ilrst more particularly to Figures l and 2, I provide a casing or container formed'in two parts, namely a'metallic housing or cover 20 and a non-conductive closing panelor base 2i.

The cover 20 is preferably rectangular in plan and lugs 22 may be formed in the corners thereof where shown, each of these lugs to have a threaded hole 23. A metallic support or bracket 24 of any approved shape is secured to the casing 20 and is the means for holding the entire switch in its proper position. I

The base 2l is of rigid insulative material such as bakelite, fibre or the like. This base is secured to the cover 20 as by means of screws 25 engaging in holes 23. Mounted on base 2| are all of the electrical elements.

Stop light incoming terminal 26 passes through and is fastened to base 2| and is the securing means for movable stop light switch contact 21, also the support for a solenoid generally indicated by the numeral 28.

Contact 21 is constructed of spring bronze in thereof.

which may be punched perforation 21 to render same more flexible also to cause the bending to be localized to desired portions thereof, and is in contact with terminal 26.

Solenoid 28 consists of a circular tube 29 upon which are rigidly fixed bre retaining Washers 3D and 3| where shown. These washers are secured to terminal 26 by supporting nibs 30B and 3|a respectively which protrude from one side The external surface of tube 29 between washers 36 and 3| is wrapped with an insulation material 32 and over this insulation are wound multiple turns of copper magnet wire forming a magnetic coil 33. It is to be here noted that the tube 29 is considerably longer than coil 33 and that said coil is located in its entirety adjacent to one end of tube 29.

Stop light continuous lighting terminal 34 passes through and is fastened to base 2| and is the securing means for the stationary stop light switch contact 35, also the support for intermittent circuit breaking contact 36.

Circuit breaker 36 is preferably constructed of spring bronze, one end being secured by and in contact with terminal 34 and the opposite end being free permits the same to flex to and from the bottom of tube 29 in the fashion of a bell armature. Two silver contact points 31 and 38 are attached to breaker 36 where shown.

Contact point 31 is directly below a third silver contact point 39, this latter being secured to a Z shaped metallic bracket 40 which in turn is fastened to the base 2| by and in contact with intermittent lighting terminal 4| which also passes through and is attached to base 2|.

Contact point 38 is located directly above a fourth silver contact point 42, which is secured to a metallic strip 43 that is stilted up from base 2| by a washer 44. Strip 43 and washer 44 are both secured to base 2| by blind eyelet rivet 45 which is also in electrical contact with strip 43.

Lead 46 extends from one end of coil 33 and is in electrical contact with rivet 45 and the opposite end of coil 33 is connected by lead 41 to one of the lugs 22 and there secured by screw 25 to form a ground 41a for the coil 33 as shown in Figures 6 and '1.

The switch contact 21 and solenoid 28 are permanently located on supporting terminal 26 by separators 26E and 26b as shown in Fig. 4. The switch contact screw 35 may be stilted up from terminal 34 by separator 35a, While the flexing strip 36 is retained in its proper position on terminal 34 by the aid of separator 34a as shown in Fig. 1. All of these separators 26a, 2Gb, 34 and 35a are preferably metallic and tubular in cross section.

Referring now to Fig. 5 the switch contact actuating means consists of a cylindrical metallic rod or axle 48 with a portion thereof bent at right angles forming a lever arm 49, near the end of which may be drilled attachment hole 50. The end of axle 48 opposite lever 49 terminates in the form of a tapered cone bearing 5|. Supported approximately midway along the axle portion 48 and rigidly secured thereto is a cam 52 of any non-yielding, electrical insulation material. Surrounding that portion of axle 48 between lever 49 and cam 52 is a loosely mounted coil tension spring 53 one end of which terminates in the form of pin 54 which is fixed into a hole in cam 52 to prevent spring 53 from rotating around axle 48, the opposite end of spring 53 terminates in a spur 55 which engages the casing 20.

The entire switch contact actuating means shown in Fig. 5 excepting lever -49 is pivotally mounted within cover 26 by means of a circular hole 56 in one side wall of cover 26 which acts as a bearing for axle 48 and in the opposite side wall of cover 29 and registering with hole 56 is a countersunk hole 51l to receive the cone bearing 5| on that end of axle 46. The coil spring 53 also exerts a compression stress against cam 52 which in turn is transmitted to axle 48 in the direction toward cone bearing 5| thus insuring the latters engagement in countersunk hole 51. The spur 55 of spring 53 may rest against the underside of top of cover 20 and be held in place there by its own tension.

The axle 48 may now be pivoted or rocked about its own axis, by pulling lever 49 to the left. This causes the cam 52 to rotate clockwise and by releasing the pull on lever 49 the spring 53 returns cam 52 counter-clockwise. The

amount of such pivoting is limited clockwise by cam 52 depressing contact 21 against contact 35 and counter-clockwise by cam 52 coming in contact with stop 58 secured to the underside of cover 20.

The contact 21 is adjusted to curve slightly upward as shown in Fig. l in solid lines and normally it is under spring pressure against the bottom of cam 52 and out of contact with contact 35. However When cam 52 is rotated to position 52-, shown by dotted lines, it depresses contact 21 to a. new position 21h, also shown in dotted lines, to touch contact 35.

The flexing strip 36 is also adjusted to curve slightly upward, as shown by dotted lines 36, thus permitting contacts 31 and 39 to touch and contacts 38 and 42 to separate, this position however is only temporary. A cylindrical plunger 59 of steel or iron is loosely placed in tube 29 intended to freely slide up and down therein, the weight of this plunger 59 causes strip 36 to bend downwardly until it reaches position 36 as shown in solid lines, when contacts 38 and 42 are in contact, while contacts 31 and 39 are open, this being the normal position of strip 36.

It may be well in some instances to provide the freely moving plunger 59 with shock absorbing and electrically insulating tips or blocks 59b and 59C of some elastic and insulating material such as rubber.

The approximate centre of gravity of plunger 59 when at the bottom of tube 29 is indicated by the letter A, however when plunger 59 has traveled the length of the tube 29 and is in position 59, as shown by dotted lines, its centre of gravity is A. The letter B indicates the centre of electromagnetic forces created by the coil 33 when energized.

Inasmuch as Fig. l illustrates the axis of the solenoid 28 in an inclined or sloped position it is to be understood that the angle of this slope may vary from about 15 to 90 from horizontal as required in any given case.

The above switch will satisfactorily operate the older type of combination automobile stop and tail lamp comprising a single lamp casing divided into two compartments, each compartment enclosing a separate single filament electric bulb. It will also operate the newer type of lamp comprising a single compartment having one bulb constructed with a double filament.

In this latter type the stop light lament isthe blinking is greatly enhanced by temporarily extinguishing the tail light filament during the intervals the stop light is in operation, I attain this improvement as follows.

Referring more particularly to Figures 2 and 3 I also provide an auxiliary tail light throwout switch enclosed within the cover 20 and mounted on base 2|. This switch consists of an incoming tail light terminal 60 and an outgoing tall light terminal 6| both of which pass through and are secured to the base 2|. The terminal 6|) is in electrical contact with and also the securing means for one end of tail light switch contact 62 which is a flexible spring bronze strip in which perforation 62a may be punched for reasons similar to those for perforation 21a. This contact 62 also is adjusted to curve slightly upward toward its free end, but unlike contact 21 in that it does not press against the bottom of cam 52 but is spaced therefrom as clearly shown in Fig. 3. The upward tendency of spring contact 62 however is arrested by coming in electrical contact with the underside of tail light switch stationary contact 63 which is pa-rt of the Z shaped metallic bracket 64 which in turn is in electrical contact with and secured to base 2| by terminal 6|. Contacts 62 and 63 are normally touching.

There is absolutely no electrical contact between any of the electrical elements shown in Fig. l with those shown in Fig. 3, it will however be noted that the cam. 52 straddles both contacts 21 and 62 and its actuation simultaneously depresses them both, which thus separates the normally closed contacts 62 and 63.

Referring now to Figures 6 and '7 the numeral indicates the usual foot brake pedal of an automobile operating the brake rod 66 to which is attached one end of draw link 61 the opposite end of which is secured in hole 50 in lever 49.

The electrical energy is 4derived from the customary storage battery or other source 68 of substantially constant and unbroken electric current connected at one side to ground at 69 and at the other side through a fuse 10.

Beyond the fuse 10 the current path bifurcates. One branch line 1| leads to the terminal 26. The other branch line 12 of the current path leads to switch 13.

The switch 13 may be thought of as the automobile lighting switch, such as a turn switch, push button, or the like independently operable by the driver and mounted in any convenient location for manual or other operation. It controls the ow of current in line 14 which in turn supplies terminal 60.

'I'hus in the night time when switch 13 would naturally be turned on continuous current passes through terminal 68, contacts 62 and 63, down bracket 64 to terminal 6|. This current to terminal 6| will however be interrupted upon the application of the brakes as the cam 52 will open the contacts 62 and 63. In the day time the switch 13 will ordinarily be turned off" stopping the current at that point.

Current is constantly being supplied to terminal 26 to energize contact 21, as soon as the brake pedal is vdepressed the cam 52 causes contacts 21 and 35 to close the circuit, thereby supplying terminal 34 and strip 36 with continuous current.

Strip 36 being normally bent downward by the weight of plunger 59 resting thereon has closed points 38 and 42 thus energizing lead 46, coil 33, and lead 41 to ground at 41".

As the current passes through coil 33 it creates a magnetic field whose centre of force B as shown intermittent terminal 4|.

in Fig. 1 is above centre of gravity A of plunger 59 thus attracting it suddenly upward and relieving its weight on strip 36 allowing same to flex upwardly as shown at 36a sepa-rating points 38 and 42 and thereby de-energizing coil 33. jerk previously transmitted to plunger 59 causes the same to slide due to its momentum a considerable way along the inside of tube 29 until arrested by gravitation and then it slides downwardly and again restson and depresses strip 36 thus completingr a cycle of its motion.

The axis of tube 29 is preferably inclined, to take advantage of the delay caused by the friction of plunger 59 rubbing against tube 29 to prolong the cycle, also to soften the blow vof plunger 59 upon striking strip 36. Modification of this slope will modify the time consumed by one cycle.

During the period strip 36 is elevated from its normal position contact points 31 and 39 are closed permitting current to pass down bracket 40 and into terminal 4|, this current is intermittent as it will be repeatedly interrupted at each cycle upon the depression of strip 36.

'This switch is capable of operating different types of lamps also operating identical lamps in various ways either independently or simultaneously as shown by wiring diagrams in Figures 6 and 7.

Lamp 15 is intended to represent a tell-tale lamp located on the dash or instrument board or elsewhere within the car, its single filament 16 being energized by lead 11 which is joined to conductor 18 which in turn is joined to one end of branch line 19 the opposite end being connected to Thus filament 16 will be furnished intermittent current only during the application of the brakes, thereby informing lthe operator that the rear signal lamps hereinafter described are operating.

The lamp 88 is intended to represent the older type of combination stop and tail lamps for automobiles constructed with two separate compartments, each having a separate electric bulb, and each bulb having a single filament. Filament 8| lights the stop signal and is energized inter` mittently while the brakes are applied through terminal 4|, line 19, conductor 18 and lead 82. Filament 83 illuminates the tail light and receives continuous current through lead 84 which is joined to conductor 85, thence through line 14 to be controlled only by switch 13. l

The lamp 86 represents the newer type of automobile combination stop and tail lamp constructed with one compartment which encloses a single electric bulb with double filaments. Filament 81 operates the stop signal and receives intermittent current upon the depressing of brake pedal through terminal 4|, line 19 and conductor 18. Filament 88 illuminating the tail light is energized continuously from lead 89 which is joined to conductor 85, extending from line 14 to be controlled only by switch 13.

The lamp 90 is identical to lamp 86 e. g. one compartment, one bulb, double filament. The stop light filament 9| is energized intermittently while brakes are applied through terminal 4|, thence through line 19 which is joined to lead 92. The tail light filament 93 is fed by line 94 which is secured to outgoing tail light terminal 6I. Thus filament 93 is `jointly controlled by switch 13 and contacts 62 and 63 and although the former may be on the filament 93 is still subject to being extinguished temporarily while the brakes are applied, by the opening of contacts 62 and 63.

The lamp 95 is of the same type as lamps 86 and The upward and also has a double filament bulb. The stop light filament 96 and the tail light filament 91 are fed by leads 98 and 99 respectively, which in turn are joined at |00 to one end of a single conductor I0 The opposite end of this conductor is joined at |02 to one end of each of the lines 19 and 94, the opposite end of each of these lines is connected to terminals 4| and 6| respectively. In this scheme both filaments 90 and 91 are lighted or extinguished simultaneously and when lighted can either burn continuously or intermittently; however these two functions cannot occur simultaneously. Both filaments and 91 are lighted continuously or extinguished by turning switch 13 on or ofi through current received from terminal 6|. Both filaments light intermittently only upon the application of the brakes by current received through terminal 4|.v Terminals 4| and El cannot be energized at the same time as the application of the brakes causes cam 52 to close contacts 21 and 35 and thereupon open contacts 62 and 63, or vice versa.

The lamp |03 may be thought of as a tail lamp or any other lamp mounted on an automobile, comprising one compartment, enclosing a single electric bulb, with only a single filament |04, which is fed by a single conductor |05, the end of which is joined at |02 to lines 19 and 94 which in turn are fastened to terminals 4l and 6| respectively. In this arrangement the filament |04 functions identically the same as joint action of filaments 96 and 91 described in the preceding paragraph except that the former has a single filament and the latter a double filament.

Lamp |06 represents a second tell-tale lamp, identical in all respects to lamp 15 except that its single filament |01 is supplied with continuous current through lead |08 when the same is connected up with terminal 34. This filament |01 normally is extinguished and lights up only while the car brakes are applied.

While the various types of lamps are shown and described singularly it is not intended to limit the invention to the operation of one lamp as a plurality of identical lamps will function equally well.

The energizing circuit may be of the two conductor type, although for simplicity I have shown a circuit which utilizes the metallic frame of an automobile for the return conductor, and it is to be here understood that the storage battery, this switch and all of the lamps are grounded to this frame.

The embodiments of the invention herein disclosed are merely illustrative and may be modified and departed from in many ways without departing from the spirit and scope of the invention as pointed out in and limited only by the appended claims.

What is claimed is:

1. An electrical system comprising a source of substantially uninterrupted current; a circuit connected to one pole thereof and including a resilient contact member, a fixed contact member normally out of contact therewith, a second resilient contact member connected to the fixed contact and having two contact points thereon and movable therewith, a fixed contact point normally out of contact with one of the said movable contact points, a solenoid having the winding thereof connected at one end to the fixed contact point, a return connection from the other end of the solenoid winding to the other pole of the source, a second xed contact point normally in contact with the second movable contact point,

a lamp filament connected at one end to the l second fixed contact point, and a return connection from the other end of the filament to the other pole of the source; a movable weight of magnetic material within the solenoid and resting on the second resilient contact member to fiex the same and thereby to hold the first movable contact point thereon in contact with the first fixed contact point and to hold the second movable contact point out of contact with the second fixed contact point; and means actuable to force the first resilient contact member into contact with the fixed contact member.

2. An electrical system comprising a source of substantially uninterrupted current; a circuit connected to one pole thereof and including a resilient contact member, a fixed contact member normally out of contact therewith, a second resilient contact member connected to the fixed contact and having two contact points thereon and movable therewith, a fixed contact point normally out of contact with one of the said movable contact points, electrically actuated means connected at one pole thereof to the xed Contact point to flex the second resilient contact member when energized, a return connection from the other pole of the means to the other pole of the source, a second fixed contact point normally in contact with the second movable contact point, a lamp filament connected at one end to the second fixed contact point, and a return connection from the other end of the filament to the other pole of the source; and means actuable to force the first resilienty contact member into contact with the fixed contact member.

3. An electrical system comprising a source of substantially uninterrupted current; a circuit connected to one pole thereof and including a resilient contact member, a fixed contact member normally out of contact therewith, a second resilient contact member connected to the fixed contact and having two contact points thereon and movable therewith, a fixed contact point normally out of contact with one of the said movable contact points, a solenoid having the winding thereof connected at one end to the fixed contact point, a return connection from the other end of the solenoid winding to the other pole of the source, a second fixed contact point normally in Contact with the second movable contact point. a lamp filament connected at one end to the second fixed contact point, and a return connection from the other end of the filament to the other pole of the source; a movable weight of magnetic material within the solenoid and resting on the second resilient contact member'to flex the same and thereby to hold the first movable contact point thereon in contact with the first fixed contact point and to hold the second movable contact point out of contact with the second fixed contact point; a second circuit also connected to the first pole of the source and including a third resilient contact member, a second fixed contact member normally in contact therewith, a second lamp filament connected at one end to the second fixed contact member, and a return connection from the other end of the `second lamp filament to the other pole of the source; and means actuable to simultaneously force the first resilient contact member into contact with the first fixed contact member and to force the third resilient contact member out of contact with the second fixed contact member.

4. An electrical system comprising a source of substantially uninterrupted current; a circuit connected to one pole thereof and including a resilient contact member, a fixed contact member normally out of contact therewith, a second resilient contact member connected to the fixed contact and having two contact points thereon and movable therewith, a fixed contact point normally out of contact with one of the said movable contact points, electrically actuated means connected at one pole thereof to the fixed contact point to flex the second resilient contact member when energized, a return connectionfrom the other pole of the means to the other pole of the source, a second fixed contact point normally in contact with the second movable contact point, a lamp filament connected at one end to the second fixed contact point, and a return connection from the other endof the filament to the other pole of the source; a second circuit also connected to the first pole of the source and including a third resilient contact member, a second fixed contact member normally in contact therewith, a second lamp filament connected at one end to the second fixed contact member, and a return connection from the other end of the second lamp filament to the other pole of the source; and means actuable to simultaneously force the first resilient contact member into contact with the first fixed contact member and to force the third resilient Contact member out of contact with the second fixed contact member.

5. An electrical system comprising a source of current connected to a first branch point member to supply uninterrupted current thereto, a second branch point member, a first intermediate circuit interposed between and connected to the two branch point members to carry uninterrupted current therebetween when closed and including a first control switch, a second intermediate circuit interposed between and connected to the two branch point members to carry interrupted current therebetween when closed and including a second control switch, a third intermediate circuit interposed between and connected to the two branch point members and including means to interrupt current flowing in the second intermediate circuit, and means actuable to operate the two control switches simultaneously.

6. An electrical system comprising a source of current connected to a first branch point member to supply uninterrupted current thereto, a second branch point member, a first intermediate circuit interposed between and connected to the two branch point members to carry uninterrupted current therebetween when closed and including a first control switch,`a second intermediate circuit interposed between and connected to the two branch point members to carry interrupted current therebetween when closed and including a second control switch, a third intermediate circuit interposed between and connected to the two branch point members and including means to interrupt current flowing in the second intermediate circuit, and means actuable to open the first control switch and close the second control switch simultaneously and vice versa.

7. An electrical system comprising a source of current connected to a branch point member to supply uninterrupted current thereto, a first current consuming means, a second current consuming means, a first branch circuit interposed between and connected to the branch point member and to the first current consuming means to supply uninterrupted current to the means and including a first control switch, a second branch circuit interposed between and connected to the branch point member and to the second current consuming means to supply interrupted current to the second current consuming means, a second branch point member connected to both current vconsuming means, a third intermediate circuit switches simultaneously.

8. An electrical system comprising a source 'of current connected to a branch point member to supply uninterrupted current thereto, a first current consuming means, a second current consuming means, a first branch circuit interposed between and connected to the branch point member and to the first current 'consuming means to supply uninterrupted current to the means and including a first control switch, a second branch circuit interposed between and connected to the branch point member and to the second current consuming means to supply interrupted current to the second current consuming means, a second branch point member connected to both current consuming means, a third intermediate circuit interposed between and connected to the two branch point members and including means to interrupt current owing through the second intermediate circuit and a second control switch, and means actuable to open the first control switch and close the second control switch simultaneously and vice versa.

9. An electrical system comprising a source of current connected` to a first branch point member to supply uninterrupted current thereto, acurrent consuming means connected to a second branch point member, a first intermediate circuit interposed between and connected to the two branch point members to carry uninterrupted current therebetween, and a second intermediate circuit interposed between and connected to the two branch point members to carry interrupted current therebetween, in combination with a control device comprising a first resilient contact member, a first fixed contact member normally out of contact therewith, a second resilient contact member, a second fixed contact member normally in contact therewith, single means actuable to simultaneously force the first resilient member into contact with the flrst fixed contact member and the second resilient member out of contact with the second fixed contact member, a resilient support electrically connected to the first fixed contact member and having two contact points thereon movable therewith, a fixed contact point normally out of contact with the one movable contact point on the support, a second fixed contact point normally in contact with the other movable contact point on the support, and means electrically connected to the first fixed contact point and to the second branch point member to cause the support to fiex and to carry the contact points thereon alternately into and out of contact respectively with the first and second fixed contact points, the first intermediate circuit being connected to lncludethe second resilient contact member and the second fixed contact member in series therein, the second intermediate circuit y being connected to include the first movable contact point on the support and the first fixed contact point in series therein, whereby uninterrupted current will pass through the first intermediate circuit when the actuating means is not operated and interrupted current will pass through the second intermediate circuit when the actuating means is operated.

10. An electrical system comprising a source of current connected to a first branch point member to supply uninterrupted current thereto, a second branch point member, a first intermediate circuit interposed between and connected to the two branch point members to carry uninterrupted current therebetween when closed and including a rst control switch, a second intermediate circuit interposed between and connected to the two branch point members to carry interrupted current therebetween when closed and including a second control switch, a third intermediate circuit interposed between and connected to the two branch point members and including means to interrupt current nowing in the second intermediate circuit, and means actuable to operate the two control switches simultaneously, the said means to interrupt current including a fixed contact member, a resilient contact member flexible into and out of contact therewith, a weight of magnetic material resting on the resilient member to flex the same, and a solenoid surrounding the weight to lift the same from the resilient member when energized, the two contact members and the solenoid winding being connected in series between the two branch point members.

1l. An electrical system comprising a source of current connected to a branch point member to supply uninterrupted current thereto, a rst current consuming means, a second current consuming means, a first branch circuit interposed between and connected to the branch point member and to the rst current consuming means to supply uninterrupted current to the means and including a rst control switch, a second branch circuit interposed between and connected to the branch point member and tol the second current consuming means to supply interrupted current to the second current consuming means, a second branch point member connected to both current consumingmeans, a third intermediate circuit interposed between and connected to the two branch point members and including means to interrupt current flowing through the second intermediate circuit and a second control switch, and means actuable to operate the two control switches simultaneously, the said means to interrupt current including a xed contact member, a resilient contact member exible into and out of contact therewith, a weight of magnetic material resting on the resilient member to flex the same, and a solenoid surrounding the weight to lift the same from the resilient member when energized, the two contact members and the solenoid winding being connected in series between the two branch point members.

DONALD S. KENNEDY. 

